The present invention relates to security devices for dual adjacent doors.
Homes and other buildings are frequently equipped with doorways designed for dual adjacent doors which swing from hinges on opposite sides of the doorway. The dual doors typically have door handles or knobs which are adjacent near the inside edges of the dual doors.
Dual doors improve accessibility to the building and enhance the outward aesthetic appearance of the building. However, dual doors also present higher security risks than single doors.
A variety of security devices exist for locking dual doors for security purposes. Typically, such devices are fairly expensive to manufacture, require a number of parts and have strict tolerance requirements. Furthermore, locking devices are often subject to mechanical breakdown and frequently must be bolted into place on or near the doors.
I have invented a security device for securing dual adjacent doors that avoids these problems. This device is the subject of my U.S. Pat. No. 5,294,160 which recently issued on Mar. 15, 1994. My patented device includes a rigid plate with openings which fit the door knobs on adjacent doors. Sliding locking pins extend beneath the door knobs when the security device is in place. My patented device is both effective as a security device and is inexpensive to manufacture.
However, a user of some embodiments of my patented device may forget to slide the locking pins into their locking positions after the rigid plate is in place on the door knobs. Also, if the dual doors are subjected to extreme vibration one of the locking pins may be dislodged thereby allowing the security device to be disconnected from the door knobs.
For the foregoing reasons, there is a need for a security device for dual doors which:
(1) is biased toward its locked state;
(2) is self-contained without any unattached parts;
(3) is inexpensive to manufacture;
(4) does not require parts which must meet strict tolerance requirements;
(5) can be secured to dual doors in an effective manner;
(6) is easy to install and remove;
(7) does not need to be bolted into place;
(8) is lightweight and easy to store;
(9) is portable; and
(10) can hang attached to a door knob when not in use.